The present invention relates to a photographic device which photographs an image of a photographic region using an image sensor such as a CMOS image sensor or the like.
There is a per se known type of prior art photographic device which creates a synthesized image in which the width of the dynamic range has been expanded.
With this type of device, a plurality of images of the same photographic region are photographed based upon different photographic conditions. And, with this device, from this plurality of images which have been obtained by this photography, a synthesized image in which the width of the dynamic range has been expanded is created.
With the device disclosed in Japanese Laid-Open Patent Publication 2003-309766, a plurality of images of the same photographic region are photographed with different light emission amounts from a light source. And, with this photographic device, a synthesized image in which the width of the dynamic range has been expanded is created using image data which has been photographed based upon a large light emission amount in relation to portions of the photographic region which are dark, and using image data which has been photographed based upon a small light emission amount in relation to portions of the photographic region which are bright.
Furthermore, with the device disclosed in Japanese Laid-Open Patent Publication H05-176233, a plurality of images are obtained under different photographic conditions by changing the exposure time period for each image.
With the devices described above, the same photographic region is photographed a plurality of times based upon different photographic conditions. Accordingly, it has been necessary to perform reading in of the accumulated electric charge from each pixel, and photographic frame processing, a plurality of times. However, a predetermined time period (such as a vertical retrace period and the like) has been required for performing this photographic frame processing a plurality of times. Accordingly, with such prior art type photographic devices which create a synthesized image in which the width of the dynamic range has been expanded by synthesizing together images whose photographic conditions are different; there has been a limit to shortening of the processing time. Moreover, with these types of photographic devices, a complicated structure and complicated signal processing have been necessary.
Thus, the object of the present invention is to provide a photographic device which, in a short processing time period, and furthermore with a simple structure, can create a synthesized image in which the width of the dynamic range has been expanded by synthesizing together images whose photographic conditions are different.